51505661647 has 16 divisors (see below), whose sum is σ = 56606526720. Its totient is φ = 46475064000.

The previous prime is 51505661629. The next prime is 51505661659. The reversal of 51505661647 is 74616650515.

It is a cyclic number.

It is not a de Polignac number, because 51505661647 - 2²³ = 51497273039 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51505661597 and 51505661606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51505661677) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2118979 + ... + 2143147.

It is an arithmetic number, because the mean of its divisors is an integer number (3537907920).

Almost surely, 2^51505661647 is an apocalyptic number.

51505661647 is a deficient number, since it is larger than the sum of its proper divisors (5100865073).

51505661647 is a wasteful number, since it uses less digits than its factorization.

51505661647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25614.

The product of its (nonzero) digits is 756000, while the sum is 46.

The spelling of 51505661647 in words is "fifty-one billion, five hundred five million, six hundred sixty-one thousand, six hundred forty-seven".